JP2017160354A - Aqueous polyurethane resin composition, and coating material using the composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyurethane resin composition which is excellent in performances such as adhesion to a steel plate, water resistance, corrosion resistance, and alkali resistance, and is suitable for a coating material for steel plate.SOLUTION: An aqueous polyurethane resin composition is obtained by reaction of (A) an urethane prepolymer obtained by reaction of (a) polyol, (b) polyisocyanate containing a specific isocyanate compound, and (c) an anionic group-introducing agent, with (B) a chain extender containing 2-aminoethyl aminoethanol, in an aqueous dispersion.SELECTED DRAWING: None

Description

  The present invention relates to a water-based polyurethane resin composition excellent in water resistance, alkali resistance, solvent resistance, metal surface, and adhesion of a topcoat, and a coating material using the water-based polyurethane resin composition.

  Polyurethane resins are widely used in paints, adhesives, binders, coating agents and the like because they provide coatings and molded articles having wear resistance, adhesion, non-tackiness, rubber elasticity and the like. In recent years, many water-based polyurethane compositions have been reported from the viewpoint of safety against environmental pollution, occupational health, etc., but water-based polyurethane compositions are more resistant to water and heat than solvent-based or solvent-free ones. There is a problem that physical properties such as property and tensile properties are inferior.

  When using a water-based polyurethane composition as a coating material, in addition to excellent physical properties such as heat resistance, tensile properties, and breaking strength, water resistance, alkali resistance, It is also required to have excellent solvent properties. In particular, when used as a coating for metal surface treatment agents, a particularly high level of corrosion resistance is required, and when applying a top coating, adhesion to the top coating is also required, but it still has satisfactory performance. Things are not currently available.

  For example, Patent Document 1 proposes a water-dispersed polyurethane resin composition using a compound in which a long-chain alkyl group is introduced to a polyfunctional isocyanate compound. By introducing a long chain alkyl group, a water-repellent property of a urethane resin film after drying has been improved, and a paint excellent in corrosion resistance and water resistance has been proposed. The paint by this method is a useful material that can protect metal surfaces such as electrogalvanized steel sheets against chemicals such as water, oil, alkali, etc. When the paint is applied, the adhesion between the top coat and the urethane resin film is poor, and the top coat is peeled off over time.

  In order to improve the adhesion with the top coating, a hydroxyl group is introduced into the urethane resin skeleton in order to form intermolecular hydrogen bonds with the ester bond, amide bond, etc. present in the resin skeleton of the top coating. A method is mentioned. For example, in Patent Document 2, a hydroxyl group-containing polyurethane resin dispersion is prepared by reacting an epoxy compound with a hydroxyl group-containing amine compound to synthesize an epoxy prepolymer, mixing with a urethane prepolymer, and further dispersing in water. Has proposed a method of manufacturing. However, by tracing this method, the paint using the urethane resin dispersion is satisfactory in corrosion resistance, water resistance, alkali resistance, etc., although the adhesion to the top coat is improved to some extent. There wasn't. Furthermore, in the case where the compound using a long-chain alkyl group introduced in Patent Document 1 and the method using the epoxy prepolymer described in Patent Document 2 are used, the water dispersion of the urethane prepolymer cannot be performed well. There was a problem.

  Patent Document 3 proposes a water-dispersed polyurethane composition having a terminal hydroxyl group by reacting an alkanolamine with a terminal isocyanate group of a urethane prepolymer after water dispersion. However, there is no problem with the manufacturing process, but the monofunctional alkanolamine makes it difficult to increase the molecular weight of the urethane prepolymer, resulting in tensile properties. Further, a urethane resin film that was satisfactory in terms of physical properties such as breaking strength could not be obtained.

International Publication No. 2006/038466 JP 2008-063465 A Japanese Patent Laid-Open No. 2005-076013

  The problem to be solved by the present invention is to provide a water-based polyurethane resin composition having good physical properties such as tensile properties and breaking strength, excellent water resistance, corrosion resistance, and alkali resistance, and also having good adhesion to a top coating. There is to do.

  Accordingly, the present inventors diligently studied and introduced a long-chain alkyl group into the urethane resin skeleton, and further reacted with aminoethylaminoethanol after dispersing in water, thereby increasing the molecular weight of the urethane resin skeleton within the urethane resin skeleton. And water-based polyurethane resin compositions having excellent water resistance, corrosion resistance, alkali resistance and adhesion, and good physical properties such as tensile properties and breaking strength were found, and the present invention was achieved. That is, the present invention is as follows.

(Invention 1) (A) Urethane prepolymer obtained by reacting (a) a polyol component, (b) a polyisocyanate component, and (c) a component containing an anionic group introducing agent. An aqueous polyurethane resin composition obtained by dispersing in water so that the concentration is 10 to 70% by mass, and then reacting (A) the urethane prepolymer in the obtained aqueous dispersion with (B) a chain extender. Because
The (b) polyisocyanate component contains an isocyanate compound represented by the following general formula (1),
The (B) chain extender contains 2-aminoethylaminoethanol,
An aqueous polyurethane resin composition.

  (Invention 2) (b) The water-based polyurethane resin of Invention 1, wherein the polyisocyanate component comprises an isocyanate compound in which A in formula (1) is a residue obtained by removing two isocyanate groups from 1,6-hexamethylene diisocyanate. Composition.

  (Invention 3) The aqueous polyurethane resin composition of Invention 1 or 2, wherein (b) the polyisocyanate component contains an isocyanate compound represented by the above formula (1) in an amount of 10 to 50% by mass relative to the total amount.

  (Invention 4) (b) The polyisocyanate component further contains one or more compounds selected from tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and 4,4-dicyclohexylmethane diisocyanate, The water-based polyurethane resin composition in any one of invention 1-3.

  (Invention 5) The aqueous polyurethane resin composition according to any one of Inventions 1 to 4, wherein (B) the chain extender contains 2-aminoethylaminoethanol in an amount of 30 to 90% by mass relative to the total amount thereof.

  (Invention 6) A paint comprising the water-based polyurethane resin composition according to any one of Inventions 1 to 5.

  The present invention provides an aqueous polyurethane resin composition having good physical properties such as tensile properties and breaking strength. The present invention further provides a polyurethane-based paint that retains the basic performance of the urethane resin and is excellent in water resistance, corrosion resistance, alkali resistance, and adhesion to the top coat.

  Hereinafter, embodiments of the aqueous polyurethane resin composition of the present invention will be described. The aqueous polyurethane resin composition of the present invention is obtained by producing a specific (A) urethane prepolymer and reacting it with a specific (B) chain extender in an aqueous dispersion to crosslink.

[(A) Urethane prepolymer]
The (A) urethane prepolymer of the present invention is obtained by reacting (a) a polyol component, (b) a polyisocyanate component, and (c) a component containing an anionic group introducing agent. As the (A) urethane prepolymer, not only the urethane prepolymer obtained by reacting the material comprising the components (a), (b) and (c), but also the above (a), (b), ( The urethane prepolymer obtained by reacting the component c) with an optional component such as a catalyst and a crosslinking agent described later is also applicable.

((A) polyol component)
As the (a) polyol component used in the present invention, for example, (a1) polyester polyol, (a2) polycarbonate diol, (a3) polyether polyol, (a4) polyol having a number average molecular weight of less than 500 can be used.

  As the above (a1) polyester polyol, for example, a compound obtained by esterification of a low molecular weight polyol and a polycarboxylic acid, a cyclic ester compound such as ε-caprolactone, γ-valerolactone, etc., is obtained by ring-opening polymerization reaction. And these copolyesters can be used.

  Examples of the low molecular weight polyol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, and 1,2-butane. Diol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1,3 -Propanediol, neopentyl glycol, 2-buty 2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, glycerin, trimethylolpropane , Ditrimethylolpropane, tritrimethylolpropane, pentaerythritol and other aliphatic polyols; 1,4-cyclohexanedimethanol, hydrogenated bisphenol A and other aliphatic cyclic structure-containing polyols; and bisphenol A and bisphenol A alkylene oxide adducts Bisphenol type polyols such as bisphenol S and alkylene oxide adducts of bisphenol S can be used. Especially, it is preferable to use an aliphatic polyol from a viewpoint of the balance of the viscosity of a urethane prepolymer and the physical property of the urethane resin when it coats.

  Examples of the polycarboxylic acid include succinic acid, adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, dimer acid aliphatic polycarboxylic acid; 1,4-cyclohexanedicarboxylic acid, cyclohexanetricarboxylic acid, etc. Alicyclic polycarboxylic acid; orthophthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, trimellitic acid, pyromellitic Aromatic polycarboxylic acids such as acids; and anhydrides or ester derivatives thereof can be used alone or in combination of two or more thereof. Among them, strength when used as a urethane resin film and solvent resistance It is preferred to use aromatic polycarboxylic acids to improve the performance. It is more preferable to use an aromatic dicarboxylic acid.

  As said (a2) polycarbonate diol, what is obtained by making carbonate and / or phosgene react with the polyol mentioned later, for example can be used. Examples of the carbonate ester include dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, butylene carbonate, diphenyl carbonate, dinaphthyl carbonate, and phenyl naphthyl carbonate.

  Examples of the polyol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1, 3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 1,7 -Heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1,3-propanediol, Neopentyl glycol, 2-butyl-2-ethyl 1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,4-cyclohexanedimethanol, Low molecular weight dihydroxy compounds such as hydroquinone, resorcin, bisphenol A, bisphenol F, 4,4'-biphenol, polyether polyols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene adipate, polyhexamethylene Polyester polyols such as succinate and polycaprolactone can be used.

As the (a3) polyether polyol, for example, one obtained by addition polymerization of alkylene oxide using one or more compounds having two or more active hydrogen atoms as an initiator can be used.
Examples of the initiator include water, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2- Butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexane Diol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1, 3-propanediol, neopentyl glycol, 2-butyl-2-ethyl -1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, glycerin, diglycerin, trimethylolpropane, Ditrimethylolpropane, tritrimethylolpropane, 1,2,6-hexanetriol, triethanolamine, triisopropanolamine, pentaerythritol, dipentaerythritol, sorbitol, saccharose, ethylenediamine, N-ethyldiethylenetriamine, 1,2-diamino Propane, 1,3-diaminopropane, 1,2-diaminobutane, 1,3-diaminobutane, 1,4-diaminobutane, diethylenetriamine, phosphoric acid, acidic phosphate ester and the like can be used.

  Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran.

  Examples of the polyol (a4) having a number average molecular weight of less than 500 include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, diethylene glycol, triethylene glycol, 2 -Butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3 , 5-Heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol Aliphatic diols such as 1,9-nonanediol; trivalent or higher polyols such as trimethylolethane, trimethylolpropane, hexitols, pentitols, glycerin, pentaerythritol; 1,4-cyclohexanedimethanol, hydrogenated bisphenol And aliphatic cyclic structure-containing polyols such as A; and bisphenol-type polyols such as bisphenol A, alkylene oxide adducts of bisphenol A, bisphenol S, alkylene oxide adducts of bisphenol S, and the like. Among these, from the viewpoint of improving the physical properties of the urethane resin film, it is preferable to use an aliphatic diol, a trivalent or higher polyol, and a bisphenol type polyol, and it is more preferable to use an alkylene oxide adduct of bisphenol A. .

  The polyol component (a) used in the present invention may be any of the above-mentioned polyols (a1), (a2), (a3), and (a4). As the (a) polyol component, the above polyols (a1), (a2), (a3), and (a4) may be used alone, or two or more of these may be used in combination.

  In order to obtain a high-strength urethane resin film by using the aqueous polyurethane resin composition of the present invention as a coating material, (a1) a polyester polyol is preferred as the above-mentioned (a) polyol component, and an aliphatic polyol and an aromatic polycarboxylic acid are used. A polyester polyol obtained by reaction is more preferred. (A) When one or more of the above polyols (a1), (a2), and (a3) are used as the polyol component, the number average molecular weight of the (a) polyol component is preferably 700 to 5000, more Preferably it is 1000-3000. (A) In order to balance the workability during the production of the urethane prepolymer and the physical properties of the urethane resin film when the aqueous polyurethane resin composition of the present invention is used as a coating material, the above (a) polyol component is a polyol. It is preferable to contain (a4). In this case, the ratio of the polyol (a4) to the total amount of the (a) polyol component is preferably 1 to 30% by mass, and more preferably 3 to 15% by mass.

((B) polyisocyanate component)
The (b) polyisocyanate component used in the present invention contains an isocyanate compound represented by the following general formula (1).

R ¹ in the above formula (1) is preferably an alkyl group having 12 to 24 carbon atoms, and more preferably an alkyl group having 14 to 20 carbon atoms. A linear alkyl group is preferred as the alkyl group constituting R ¹ . The group A in the above formula (1) is preferably an isocyanate compound which is a residue obtained by removing two isocyanate groups from an aliphatic diisocyanate compound, more preferably two isocyanate groups from 1,6-hexamethylene diisocyanate. It is a residue excluding.

  Although the ratio of the isocyanate compound represented by the general formula (1) with respect to the total amount of the (b) polyisocyanate component of the present invention is not particularly limited, the water dispersibility of the urethane prepolymer and the aqueous polyurethane composition obtained are used as a coating film. The range of 10-50 mass% is preferable in terms of the balance with the physical properties when it is used.

  (B) The polyisocyanate component can contain an isocyanate compound other than the isocyanate compound represented by the above formula (1). Examples of such other isocyanate compounds include aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, 1,6-hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, Aliphatic or alicyclic structure-containing diisocyanates such as 4,4′-dicyclohexylmethane diisocyanate and tetramethylxylylene diisocyanate, and these aromatic diisocyanates or aliphatic or alicyclic structure-containing diisocyanates were trimerized. Compounds and the like can be used. These may be used alone, or two or more of these may be used in combination. As these other isocyanate compounds, 4,4'-dicyclohexylmethane diisocyanate, tolylene diisocyanate, and isophorone diisocyanate are preferable in that they are available at low cost.

((C) Anionic group introduction agent)
Examples of the anionic group introducing agent (c) used in the present invention include polyols containing carboxyl groups such as dimethylolpropionic acid, dimethylolbutanoic acid, dimethylolbutyric acid, dimethylolvaleric acid, and 1,4-butane. Polyols containing sulfonic acid groups such as diol-2-sulfonic acid can be used. In these, the polyol containing a carboxyl group is preferable at a point with easy acquisition, and dimethylol propionic acid is more preferable.
(Amount of (a), (b), (c))
In general, when a urethane prepolymer is produced by reacting a polyol, a polyisocyanate, and an anionic group introducing agent, the total isocyanate group equivalent (NCO) of the polyisocyanate and all hydroxyl groups contained in the polyol and the anionic group introducing agent The terminal structure of the urethane prepolymer obtained varies depending on the ratio of equivalent weight (OH). When NCO / OH is less than 1.0, that is, when the number of hydroxyl groups in the reaction component is excessive, a urethane prepolymer having a terminal hydroxyl group is obtained. When the ratio NCO / OH is 1.0 or more, that is, when the number of isocyanate groups in the reaction component is excessive, a urethane prepolymer whose end groups are isocyanate groups is obtained. Urethane prepolymers whose end groups are isocyanate groups have higher water dispersibility than urethane prepolymers whose end groups are hydroxyl groups, and are easily polymerized by chain extension. Accordingly, the urethane prepolymer (A) of the present invention is preferably a urethane prepolymer whose terminal group is an isocyanate group.
However, when the ratio NCO / OH is 1.0 or more and less than 1.1, a relatively high molecular weight urethane prepolymer is obtained, and such a high molecular weight urethane prepolymer tends to have poor water dispersibility. There is. In this case, the storage stability of the finally obtained aqueous polyurethane resin composition may be deteriorated. Further, when the ratio NCO / OH exceeds 2.5, the product contains a high concentration of isocyanate groups, and therefore, when the obtained prepolymer is dispersed in water, the isocyanate groups and water react to cause carbon dioxide. This may cause problems during production such as rapid foaming. Moreover, in this case, there is a possibility that the adhesiveness between the coating film made of the obtained water-based polyurethane composition and the substrate is lowered.
Therefore, when the (A) urethane prepolymer of the present invention is produced, the above (a) polyol component, (b) polyisocyanate component, and (c) an anionic group introducing agent are all added to the (b) polyisocyanate component. The ratio (NCO / OH) of the isocyanate group equivalent (NCO) to the total hydroxyl equivalent (OH) contained in the (a) polyol component and (c) anionic group introducing agent is preferably 1.1 to 2.5, more preferably Is blended in an amount ratio of 1.2 to 2.0, particularly preferably 1.3 to 1.8.

((A) Acid value of urethane prepolymer)
In the present invention, considering the dispersibility of (A) the urethane prepolymer in water and the water resistance of the urethane film made of the aqueous polyurethane resin composition, the acid value of the (A) urethane prepolymer is preferably 10 to 80 mgKOH / g, more preferably in the range of 20-50 mg KOH / g. The anionic group introducing agent (c) is used in an amount corresponding to the acid value of the (A) urethane prepolymer. In addition, the acid value of the above-mentioned (A) urethane prepolymer is the theoretical value calculated | required from the compounding quantity of the reaction component of a urethane prepolymer (A). As described later, when an inert solvent is used in the production of the urethane prepolymer (A), the measured value of the acid value of the obtained (A) urethane prepolymer varies from the above theoretical value. The following relationship exists between the above theoretical values and measured values.
Acid value (theoretical value)
= Acid value (measured value) x {(a) + (b) + (c) + solvent: total mass} / {(a) + (b) + (c): total mass}
(catalyst)
In the production of the (A) urethane prepolymer of the present invention, a catalyst can be used as necessary. Examples of such catalysts include N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetramethylpropylenediamine, N, N, N ′, N ″, N ′. '-Pentamethyldiethylenetriamine, N, N, N', N ", N" -pentamethyl- (3-aminopropyl) ethylenediamine, N, N, N ', N ", N" -pentamethyldipropylene Triamine, N, N, N ′, N′-tetramethylguanidine, 1,3,5-tris (N, N-dimethylaminopropyl) hexahydro-S-triazine, 1,8-diazabicyclo [5.4.0] Undecene-7, triethylenediamine, N, N, N ′, N′-tetramethylhexamethylenediamine, N-methyl-N ′-(2-dimethylaminoethyl) piperazine, N, N′-dimethylpiperazine, dimethyl silane Chlorhexylamine, N-methylmorpholine, N-ethylmorpholine, bis (2-dimethylaminoethyl) ether, N, N-dimethyllaurylamine, 1-methylimidazole, 1,2-dimethylimidazole, 1-isobutyl-2- Tertiary amines such as methylimidazole and 1-dimethylaminopropylimidazole can be used.

  In addition, tetraalkylammonium halides such as tetramethylammonium chloride, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide, tetraalkylammonium organic acid salts such as tetramethylammonium 2-ethylhexanoate, etc. Quaternary ammonium salt, stanas diacetate, stanas dioctoate, stanas dioleate, stanas dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dioctyltin dilaurate, lead octoate, lead naphthenate Organic metal catalysts such as nickel naphthenate and cobalt naphthenate can also be used.

These catalysts may be used alone or in combination of two or more. Among these catalysts, organometallic catalysts are preferable from the viewpoint of low yellowing and good reactivity, and dibutyltin dilaurate or dioctyltin dilaurate is more preferable. The amount of such a catalyst is not particularly limited, but is preferably 0.001 to 1% by mass with respect to the total amount of (a) polyol component, (b) polyisocyanate component, and (c) anionic group introducing agent. Yes, more preferably 0.01 to 0.1% by mass.
(Crosslinking agent)
In the production of the urethane prepolymer (A) of the present invention, a crosslinked structure can be introduced into the urethane prepolymer (A) using a crosslinking agent. As the crosslinking agent, a crosslinking agent usually used at the time of synthesizing the urethane prepolymer can be used without limitation. Examples of such crosslinking agents include melamine, monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine, methylated methylol melamine, butylated methylol melamine, melamine resin, etc. can do. The crosslinking agent used in the present invention is preferably melamine which is excellent in dispersibility in polyurethane and is inexpensive. The amount of the crosslinking agent used is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the (a) polyol component.

(Production of urethane prepolymer (A))
The (A) urethane prepolymer used in the present invention comprises (a) a polyol component, (b) a polyisocyanate component, (c) an anionic group introducing agent, an optional catalyst and / or a crosslinking agent, and an optional inert solvent. It is obtained by reacting in the presence of As the inert solvent used at this time, acetone, methyl ethyl ketone, dioxane, tetrahydrofuran, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone or the like having a high affinity for water can be used. When using a solvent having a boiling point of 100 ° C. or lower, it is preferable to synthesize the aqueous polyurethane resin of the present invention and then remove the solvent by distillation under reduced pressure or the like. Although the usage-amount of a solvent is not restrict | limited in particular, Preferably it is 3-200 mass parts with respect to 100 mass parts of whole quantity of the raw material of (A) urethane prepolymer.
[(A) Water dispersion of urethane prepolymer]
In the present invention, (A) the urethane prepolymer thus obtained is dispersed in water and then reacted with (B) a chain extender. In the present invention, the method for dispersing the urethane prepolymer (A) in water is not particularly limited. For example, the following prepolymer mixing method and phase inversion method can be used.

(Prepolymer mixing method)
(A) An anionic group neutralizing agent is added to the urethane prepolymer, and the resulting urethane prepolymer mixture is poured into water and dispersed in water using means such as a homomixer or a disper. In addition, an emulsifier can be previously added to water before a urethane prepolymer mixture is thrown in.

(Phase inversion method)
(A) An anionic group neutralizing agent is added to the urethane prepolymer, water is further added, and the mixture is stirred as necessary using a means such as a homomixer or a disper to obtain an aqueous dispersion of the urethane prepolymer. In addition, water to which an anionic group neutralizing agent and / or an emulsifier has been added in advance can be added.

(Anionic group neutralizer)
Examples of the anionic group neutralizing agent include trialkylamines such as trimethylamine, triethylamine, and tributylamine; N, N-dimethylethanolamine, N, N-dimethylpropanolamine, N, N-dipropylethanolamine, 1-dimethyl Tertiary amine compounds of trialkanolamines such as N, N-dialkylalkanolamines such as amino-2-methyl-2-propanol, N-alkyl-N, N-dialkanolamines and triethanolamine; ammonia; Basic compounds such as trimethylammonium hydroxide, sodium hydroxide, potassium hydroxide, and lithium hydroxide can be used. These compounds can be used alone, or two or more of these compounds can be used in combination.

From the viewpoint of improving the weather resistance and water resistance of the dried product of the aqueous polyurethane resin composition of the present invention, the anionic group neutralizing agent is preferably a highly volatile anionic group neutralizing agent that is easily dissociated by heat. . Particularly preferred anionic group neutralizing agents are trimethylamine and / or triethylamine.
In view of storage stability of water-based polyurethane resin composition, mechanical properties such as strength of coating film made of water-based polyurethane resin composition, water resistance of coating film made of water-based polyurethane resin composition, etc. The amount used is preferably 0.5 to 2.0 equivalents, more preferably 0.8 to 1.5 equivalents, per 1 equivalent of anionic group.

(emulsifier)
A known surfactant can be used as the emulsifier. For example, general anionic surfactants and nonionic surfactants as surfactants, cations such as primary amine salts, secondary amine salts, tertiary amine salts, quaternary amine salts and pyridinium salts An amphoteric surfactant such as a surfactant, betaine type, sulfate type and sulfonic acid type can be used.

  Examples of the anionic surfactant include alkyl sulfates such as sodium dodecyl sulfate, potassium dodecyl sulfate, and ammonium dodecyl sulfate; polyoxyethylene ether sulfates such as sodium dodecyl polyglycol ether sulfate and ammonium polyoxyethylene alkyl ether sulfate; Alkyl sulfonates such as ricinolate, alkali metal salt of sulfonated paraffin, ammonium salt of sulfonated paraffin; fatty acid salts such as sodium laurate, triethanolamine oleate, triethanolamine abiate; sodium benzenesulfonate, alkali phenol hydroxy Alkyl aryl sulfos such as alkali metal sulfates of ethylene It can be used over door class. In addition, high alkyl naphthalene sulfonate, naphthalene sulfonate formalin condensate, dialkyl sulfosuccinate, polyoxyethylene alkyl sulfate salt, polyoxyethylene alkyl aryl sulfate salt, polyoxyethylene ether phosphate, polyoxyethylene alkyl ether acetic acid A salt, an N-acylamino acid salt, an N-acylmethyltaurine salt, and the like can also be used.

  As the nonionic surfactant, fatty acid partial esters of polyhydric alcohols such as sorbitan monolaurate and sorbitan monooleate, polyoxyethylene glycol fatty acid esters, and polyglycerin fatty acid esters can be used. Furthermore, ethylene oxide and / or propylene oxide adduct of alcohol having 1 to 18 carbon atoms, ethylene oxide and / or propylene oxide adduct of alkylphenol, ethylene oxide and / or propylene oxide adduct of alkylene glycol and / or alkylene diamine, etc. Can be used.

  Examples of the alcohol having 1 to 18 carbon atoms constituting the nonionic surfactant include methanol, ethanol, propanol, 2-propanol, butanol, 2-butanol, tertiary butanol, amyl alcohol, isoamyl alcohol, tertiary amyl alcohol, Examples include hexanol, octanol, decane alcohol, lauryl alcohol, myristyl alcohol, palmityl alcohol, and stearyl alcohol.

  Examples of the alkylphenol include phenol, methylphenol, 2,4-di-tert-butylphenol, 2,5-di-tert-butylphenol, 3,5-di-tert-butylphenol, and 4- (1,3-tetramethylbutyl) phenol. 4-isooctylphenol, 4-nonylphenol, 4-tert-octylphenol, 4-dodecylphenol, 2- (3,5-dimethylheptyl) phenol, 4- (3,5-dimethylheptyl) phenol, naphthol, bisphenol A, And bisphenol F and the like.

  Examples of the alkylene glycol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, etc. It is.

The alkylene diamine is, for example, a compound in which the alcoholic hydroxyl group of the alkylene glycol described above is substituted with an amino group. As the ethylene oxide and propylene oxide adduct, both random adducts and block adducts can be used.
Examples of the cationic surfactant include lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, distearyldimethylammonium chloride, didecyldimethylammonium chloride, laurylbenzyldimethylammonium chloride, didecyldimethylammonium chloride, alkylpyridinium bromide and imidazolinium. Laurate or the like can be used.

  Examples of the amphoteric surfactant include coconut oil fatty acid amidopropyldimethylacetate betaine, lauryldimethylamino acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxymethylimidazolinium betaine, laurylhydroxysulfobetaine, lauroylamidoethylhydroxyethyl. Betaine-type amphoteric surfactants such as carboxymethyl betaine and metal salts of hydroxypropyl phosphate, amino acid-type amphoteric surfactants such as metal salts of β-laurylaminopropionic acid, sulfate-type amphoteric surfactants and sulfonic-acid-type amphoteric Surfactants can be used.

  Nonionic surfactants are preferred as emulsifiers because they are easily available and inexpensive, fatty acid partial esters of polyhydric alcohols such as sorbitan monolaurate and sorbitan monooleate, ethylene oxides of alcohols having 1 to 18 carbon atoms, and A propylene oxide adduct is more preferred.

Although the usage-amount of the said emulsifier is not restrict | limited, From viewpoints, such as the water resistance of the coating film which consists of an aqueous polyurethane resin composition, Preferably it is 0-30 mass parts with respect to 100 mass parts of total amounts of a urethane prepolymer composition. More preferably, it is 0-20 mass parts. When emphasizing the water resistance of the coating film made of the aqueous polyurethane resin composition, it is preferable to minimize the amount of the emulsifier used.
[(B) chain extender]]
The water-based polyurethane resin composition of the present invention is obtained by adding a specific (B) chain extender to the water-dispersed (A) urethane prepolymer obtained by using the above-described methods and materials, and (A) the urethane prepolymer. It is obtained by introducing a crosslinked structure into By increasing the molecular weight of the (A) urethane prepolymer by crosslinking, the physical properties when the aqueous polyurethane resin composition of the present invention is used as a film are improved.

The (B) chain extender used in the present invention is characterized by containing aminoethylaminoethanol. Aminoethylaminoethanol is a compound having good solubility in water and having both an amino group and a hydroxyl group. (A) Since the amino group preferentially reacts with the terminal isocyanate group in the urethane prepolymer, as a result, a hydroxyl group having a low reactivity is left in the urethane resin, and the aqueous polyurethane resin containing the hydroxyl group A composition can be obtained. The content of aminoethylaminoethanol in the (B) chain extender is not particularly limited, but is preferably 30 to 90% by mass, more preferably 50 to 70% by mass, based on the total amount of the (B) chain extender.
(B) As chain extender, in addition to aminoethylaminoethanol, for example, mensendiamine, isophoronediamine, norbornenediamine, aminoethylaminoethanol, bis (4-amino-3-methyldicyclohexyl) methane, diaminodicyclohexylmethane, Alicyclic diamines such as bis (aminomethyl) cyclohexane, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro (5,5) undecane; m-xylenediamine, α -(M / p-aminophenyl) ethylamine, m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodimethyldiphenylmethane, diaminodiethyldiphenylmethane, dimethylthiotoluenediamine, diethyltoluenediamine, α Polyamines of aromatic diamines such as .alpha .'- bis (4-aminophenyl) -p-diisopropylbenzene can also be used. Further, succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, phthalic acid dihydrazide, 1,6-hexamethylenebis (N, N-dimethylsemicarbazide), 1,1,1 ′, 1′-tetramethyl-4,4 ′ Hydrazines such as-(methylene-di-para-phenylene) disemicarbazide, hydrazine hydrate, and water can also be used. Among these, diamines, hydrazides, hydrated hydrazine, and water are preferable, and ethylenediamine, adipic acid dihydrazide, hydrated hydrazine, and water are particularly preferable.
(B) Although the usage-amount of a chain extender is not restrict | limited especially, with respect to the physical property etc. of the coating film which consists of an aqueous polyurethane resin composition of this invention, with respect to the isocyanate group equivalent contained in the (A) urethane prepolymer before chain extension reaction. (B) The quantity from which the ratio of the isocyanate reactive group equivalent contained in a chain extender becomes the range of 0.1-1.0 is preferable.
[Water-based polyurethane resin composition]
The aqueous polyurethane resin composition of the present invention contains a specific polyurethane resin as a main component. The polyurethane resin contained in the aqueous polyurethane resin composition of the present invention is obtained by reacting the above-mentioned (a) polyol component, (b) polyisocyanate component, and (c) an anionic group introducing agent. The polymer is obtained by increasing the molecular weight in water with the above-mentioned (B) chain extender. The repeating unit of the polyurethane resin contained in the water-based polyurethane resin composition of the present invention is not uniform, and its structure and repeating number are varied. Therefore, the structure of the polyurethane resin contained in the aqueous polyurethane resin composition of the present invention is very complicated. For this reason, the structure of the polyurethane resin finally contained in the water-based polyurethane resin composition of the present invention cannot be uniformly expressed by a certain general formula. Therefore, in the present invention, an aqueous polyurethane resin composition characterized by containing such a polyurethane resin is reacted with “(a) a polyol component, (b) a polyisocyanate component, and (c) an anionic group introducing agent. The (A) urethane prepolymer obtained is dispersed in water so that the concentration of the (A) urethane prepolymer is 10 to 70% by mass, and then the (A) urethane prepolymer in the obtained aqueous dispersion (B) an aqueous polyurethane resin composition obtained by reacting with a chain extender, wherein the (b) polyisocyanate component contains an isocyanate compound represented by the general formula (1), and the (B) chain It must be defined by the expression “aqueous polyurethane resin composition in which the extender contains 2-aminoethylaminoethanol”.
[Additive]
Additives can be added to the water-based polyurethane resin composition of the present invention as long as the effects of the present invention are not impaired. As the additive, various general resin additives can be used without limitation. Examples of such additives include cross-linking agents, various weathering agents (hindered amine light stabilizers, UV absorbers and antioxidants), coupling agents that particularly enhance adhesion to substrates, and adhesion promotion other than coupling agents. Agent, inorganic colloidal sol such as colloidal silica or colloidal alumina, tetraalkoxysilane and its condensation polymer, chelating agent, epoxy compound, pigment, dye, film-forming aid, curing agent, external cross-linking agent, viscosity modifier, leveling agent, Antifoaming agent, anticoagulant, radical scavenger, heat resistance imparting agent, inorganic or organic filler, plasticizer, lubricant, antistatic agent such as fluorine or siloxane, reinforcing agent, catalyst, thixotropic agent, wax Antifogging agents, antibacterial agents, antifungal agents, antiseptic and antirust agents, and rust inhibitors can be used.

  Examples of the crosslinking agent include adducts of urea, melamine, benzoguanamine, and the like with formaldehyde, amino resins composed of the adducts and alkyl ether compounds containing an alcohol unit having 1 to 6 carbon atoms, and polyfunctional epoxy compounds; Polyfunctional isocyanate compound; Block isocyanate compound; Polyfunctional aziridine compound, etc. are mentioned. Specific examples of these include oxazoline compounds, epoxy compounds, carbodiimide compounds, aziridine compounds, melamine compounds, and zinc complexes.

  Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5′-methylenebis (2-hydroxy-4-methoxybenzophenone). 2-hydroxybenzophenones such as 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, 2- (2-hydroxy-3, 5-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3,5 -Dicumylphenyl) benzotriazole, 2,2'-methylenebis (4- 3-octyl-6-benzotriazolylphenol), 2- (2-hydroxy-3-tert-butyl-5-carboxyphenyl) benzotriazole polyethylene glycol ester, 2- [2-hydroxy-3- (2-acryloyl) Oxyethyl) -5-methylphenyl] benzotriazole, 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-butylphenyl] benzotriazole, 2- [2-hydroxy-3- (2) -Methacryloyloxyethyl) -5-tert-octylphenyl] benzotriazole, 2- [2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-butylphenyl] -5-chlorobenzotriazole, 2- [ 2-hydroxy-5- (2-methacryloyloxyethyl) phenyl] benzene Nzotriazole, 2- [2-hydroxy-3-tert-butyl-5- (2-methacryloyloxyethyl) phenyl] benzotriazole, 2- [2-hydroxy-3-tert-amyl-5- (2-methacryloyl) Oxyethyl) phenyl] benzotriazole, 2- [2-hydroxy-3-tert-butyl-5- (3-methacryloyloxypropyl) phenyl] -5-chlorobenzotriazole, 2- [2-hydroxy-4- (2) -Methacryloyloxymethyl) phenyl] benzotriazole, 2- [2-hydroxy-4- (3-methacryloyloxy-2-hydroxypropyl) phenyl] benzotriazole, 2- [2-hydroxy-4- (3-methacryloyloxypropyl) ) Phenyl] benzotriazole and the like 2- (2-hydroxyphene) B) benzotriazoles; 2- (2-hydroxy-4-methoxyphenyl) -4,6-diphenyl-1,3,5-triazine, 2- (2-hydroxy-4-hexyloxyphenyl) -4,6 -Diphenyl-1,3,5-triazine, 2- (2-hydroxy-4-octoxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [ 2-hydroxy-4- (3-C12-C13 mixed alkoxy-2-hydroxypropoxy) phenyl] -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- [2- Hydroxy-4- (2-acryloyloxyethoxy) phenyl] -4,6-bis (4-methylphenyl) -1,3,5-triazine, 2- (2,4-dihydroxy-3-allylphene) ) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4,6-tris (2-hydroxy-3-methyl-4-hexyloxyphenyl) -1, 2- (2-hydroxyphenyl) -4,6-diaryl-1,3,5-triazines such as 3,5-triazine; phenyl salicylate, resorcinol monobenzoate, 2,4-di-tert-butylphenyl-3, 5-di-tert-butyl-4-hydroxybenzoate, octyl (3,5-di-tert-butyl-4-hydroxy) benzoate, dodecyl (3,5-di-tert-butyl-4-hydroxy) benzoate, tetradecyl (3 5-di-tert-butyl-4-hydroxy) benzoate, hexadecyl (3,5-di-tert-butyl-4-hydroxy) benzoate, octadecyl (3,5-di) Benzoates such as tert-butyl-4-hydroxy) benzoate and behenyl (3,5-ditert-butyl-4-hydroxy) benzoate; 2-ethyl-2′-ethoxyoxanilide, 2-ethoxy-4′- Substituted oxanilides such as dodecyl oxanilide; Cyanoacrylates such as ethyl-α-cyano-β, β-diphenyl acrylate, methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate; and various Metal salts or metal chelates such as nickel or chromium salts or chelates are used.

  As the antioxidant, phosphorus antioxidants, phenol antioxidants, sulfur antioxidants can be used. Examples of phosphorus antioxidants include triphenyl phosphite, tris (2,4-di-tert-butylphenyl) phosphite, tris (2,5-di-tert-butylphenyl) phosphite, and tris (nonylphenyl). Phosphite, tris (dinonylphenyl) phosphite, tris (mono, dimixed nonylphenyl) phosphite, diphenyl acid phosphite, 2,2′-methylenebis (4,6-ditertiarybutylphenyl) octyl phosphite, Diphenyldecyl phosphite, diphenyloctyl phosphite, di (nonylphenyl) pentaerythritol diphosphite, phenyl diisodecyl phosphite, tributyl phosphite, tris (2-ethylhexyl) phosphite, tridecyl phosphite, trilauryl phosphite, Butyl acid phosphite, dilauryl acid phosphite, trilauryl trithiophosphite, bis (neopentylglycol) -1,4-cyclohexanedimethyldiphosphite, bis (2,4-ditertiarybutylphenyl) pentaerythritol diphos Phyto, bis (2,5-ditertiarybutylphenyl) pentaerythritol diphosphite, bis (2,6-ditertiarybutyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4-dicumyl) Phenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, tetra (mixed alkyl of C12 alkyl to C15 alkyl) -4,4'-isopropylidenediphenyl phosphite, bis [2,2'-methylenebis (4 6-dia Milphenyl)]-isopropylidene diphenyl phosphite, tetratridecyl-4,4′-butylidenebis (2-tert-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1,1,3-tris (2- Methyl-5-tert-butyl-4-hydroxyphenyl) butane triphosphite, tetrakis (2,4-ditert-butylphenyl) biphenylene diphosphonite, tris (2-[(2,4,7,9-tetrakis) Tert-butyldibenzo [d, f] [1,3,2] dioxaphosphin-6-yl) oxy] ethyl) amine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene- 10-oxide, tris (2-[(2,4,8,10-tetrakis tert-butyldibenzo [d, f] [1,3,2] dioxaphos Epin-6-yl) oxy] ethyl amine, 2- (1,1-dimethylethyl) -6-methyl-4- [3-[[2,4,8,10-tetrakis (1,1-dimethylethyl) Dibenzo [d, f] [1,3,2] dioxaphosphin-6-yl] oxy] propyl] phenol and 2-butyl-2-ethylpropanediol-2,4,6-tritert-butylphenol Monophosphite or the like can be used.

  Examples of the phenol-based antioxidant include 2,6-ditertiarybutyl-p-cresol, 2,6-diphenyl-4-octadecyloxyphenol, stearyl (3,5-ditertiarybutyl-4- Hydroxyphenyl) propionate, distearyl (3,5-ditertiarybutyl-4-hydroxybenzyl) phosphonate, tridecyl 3,5-ditertiarybutyl-4-hydroxybenzylthioacetate, thiodiethylenebis [(3,5 -Di-tert-butyl-4-hydroxyphenyl) propionate], 4,4'-thiobis (6-tert-butyl-m-cresol), 2-octylthio-4,6-di (3,5-di-tert-butyl) -4-hydroxyphenoxy) -s-triazine, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), bis [3,3- (4-hydroxy-3-tert-butylphenyl) butyric acid] glycol ester, 4,4′-butylidenebis (2,6-ditert-butylphenol), 4,4′-butylidenebis (6-tert-butyl- 3-methylphenol), 2,2′-ethylidenebis (4,6-di-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, bis [2-tert-butyl-4-methyl-6- (2-hydroxy-3-tert-butyl-5-methylbenzyl) phenyl] terephthalate, 1,3,5-tris (2,6-dimethyl-3-hydroxy -4-tert-butylbenzyl) isocyanurate, 1,3,5-tris (3,5-ditert-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tri (3,5-di-tert-butyl-4-hydroxybenzyl) -2,4,6-trimethylbenzene, 1,3,5-tris [(3,5-di-tert-butyl-4-hydroxyphenyl) propionyl Oxyethyl] isocyanurate, tetrakis [methylene-3- (3 ′, 5′-ditert-butyl-4′-hydroxyphenyl) propionate] methane, 2-tert-butyl-4-methyl-6- (2-acrolate) Yloxy-3-tert-butyl-5-methylbenzyl) phenol, 3,9-bis [2- (3-tert-butyl-4-hydroxy-5-methylhydrocinnamoyloxy) -1,1-dimethylethyl ] -2,4,8,10-tetraoxaspiro [5.5] undecane, triethylene glycol bis [β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propyl Lopionate], tocopherol and the like can be used.

  Examples of the sulfur-based antioxidant include dialkylthiodipropionates such as dilauryl, dimyristyl, myristyl stearyl, and distearyl esters of thiodipropionic acid, and pentaerythritol tetra (β-dodecyl mercaptopropionate). The β-alkyl mercaptopropionic esters of polyols can be used.

  The amount of the weathering agent (hindered amine light stabilizer, ultraviolet absorber and antioxidant) used is preferably 0.001 to 10 parts by mass, more preferably 100 parts by mass based on the solid content of the aqueous polyurethane resin composition. 0.01 to 5 parts by mass. If the amount of the weathering agent is less than 0.001 part by mass with respect to 100 parts by mass of the solid content, a sufficient addition effect may not be obtained. If the amount of the weathering agent is more than 10 parts by mass with respect to 100 parts by mass of the solid content, the water dispersion stability and the physical properties of the coating film may be adversely affected.

  As a method of adding these weathering agents, a method of adding to a urethane raw material polyol, a method of adding to a urethane prepolymer, a method of adding to a water phase during water dispersion of the urethane prepolymer, a method of adding after water dispersion Either is fine. In terms of easy operation, a method of adding to the raw material polyol and a method of adding to the urethane prepolymer are preferred.

  Examples of the coupling agent include γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -N′-β- (amino Ethyl) -γ-aminopropyltriethoxysilane, γ-anilinopropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, vinyltriethoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-isocyanatopropyl Silane couplings such as triethoxysilane Agents: isopropyl triisostearoyl titanate, isopropyl tri-n-dodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, tetra ( 2,2-diallyloxymethyl-1-butyl) bis (di-tridecyl) phosphite titanate, bis (dioctylpyrophosphate) oxyacetate titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacryloyl Isostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri (di Octyl phosphate) titanate, isopropyl tricumyl phenyl titanate, isopropyl tri (N-aminoethyl-aminoethyl) titanate, tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetrakis (2-ethylhexyl) titanate, tetrastearyl titanate, tetra Methyl titanate, diethoxybis (acetylacetonato) titanium, diisopropylbis (acetylacetonato) titanium, diisopropoxybis (ethylacetoacetate) titanium, isopropoxy (2-ethyl-1,3-hexanediolato) titanium, di ( 2-ethylhexoxy) bis (2-ethyl-1,3-hexanediolato) titanium, di-n-butoxybis (triethanolaminato) titanium, tetra Titanium coupling agents such as acetylacetonate titanium, hydroxybis (lactato) titanium, dicumylphenyloxyacetate titanate, diisostearoylethylene titanate; zirconium tributoxy systemate, tetra (2,2-diallyloxymethyl) butyldi (ditridecyl) ) Phosphitozirconate, Neopentyl (diallyl) oxytrineodecanoyl zirconate, Neopentyl (diallyl) oxytri (dodecyl) benzene-sulfonyl zirconate, Neopentyl (diallyl) oxytri (dioctyl) phosphato zirconate, Neopentyl (diallyl) oxytri (Dioctyl) pyro-phosphato zirconate, neopentyl (diallyl) oxytri (N-ethylenediamino) ethyl zirconate, neo Nethyl (diallyl) oxytri (m-amino) phenyl zirconate, neopentyl (diallyl) oxytrimethacrylic zirconate, neopentyl (diallyl) oxytriacrylic zirconate, dineopentyl (diallyl) oxydiparaaminobenzoyl zirconate, dineopentyl (diallyl) oxydi (3-mercapto) propyl zirconate, tetranormal propoxyzirconium, tetranormalbutoxyzirconium, zirconium 2,2-bis (2-propenolatomethyl) butyrate, zirconium tetraacetylacetonate, zirconium tributoxyacetylacetonate, zirconium di Butoxybis (acetylacetonate), zirconium dibutoxybis (acetylacetonate), zirconium trib Acetoacetate, can be mentioned zirconium coupling agents such as zirconium monobutoxy acetylacetonate bis (ethylacetoacetate).

  Among these coupling agents, it is preferable to use a silane coupling agent from the viewpoint of improving the adhesion to the metal surface and the compatibility of the aqueous polyurethane resin composition, and it is coupled to the urethane resin skeleton. In view of incorporating a functional group, it is more preferable to use a silane coupling agent containing an amino group.

  As a method for adding the coupling agent, (A) the urethane prepolymer may be added before being dispersed in water or after being dispersed in water, but the storage stability of the produced aqueous polyurethane resin composition may be added. From the viewpoint of properties, a method of adding before dispersing in water is preferable.

  The amount of the coupling agent used is not particularly limited as long as it is an effective amount or more. Preferably it is 0.01-1 mass% with respect to the total amount of an agent and an additive, More preferably, it is 0.1-0.5 mass%.

  Examples of the adhesion promoter other than the coupling agent include benzimidazole, benzoxazole, benzthiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzthiazole, 3-morpholinomethyl-1-phenyl- Examples include triazole-2-thione, 5-amino-3-morpholinomethyl-thiazole-2-thione, 2-mercapto-5-methylthio-thiadiazole, triazole, tetrazole, benzotriazole, carboxybenzotriazole, amino group-containing benzotriazole, and the like. It is done. Of these, benzotriazole is preferably used.

The use amount of the adhesion promoter other than the coupling agent is not particularly limited as long as it is an effective amount or more, but (a) a polyol component, (b) a polyisocyanate component, and (c) an anionic group introducing agent, and optionally. Preferably it is 0.01-1 mass% with respect to the total amount of the catalyst mix | blended, a crosslinking agent, and an additive, More preferably, it is 0.1-0.5 mass%.
[Usage]
Applications of the water-based polyurethane resin composition of the present invention include paints, adhesives, surface modifiers, organic and / or inorganic powder binders, molded articles, and the like. Specifically, glass fiber sizing agent, thermal paper coating agent, inkjet recording paper coating agent, printing ink binder agent, steel plate coating agent, agricultural film coating agent, glass, slate, concrete and other inorganic structures Examples thereof include material paints, woodwork paints, fiber treatment agents, sponges, puffs, gloves, and condoms. Among these, the water-based polyurethane resin composition of the present invention is preferably used as a coating material for paints, wood, paper, fibers, glass, electronic material parts and steel plates, more preferably as a paint for surface-treated steel plates.

  The paint using the aqueous polyurethane resin composition of the present invention includes other resins, pigments, thickeners, curing catalysts, ultraviolet absorbers, light stabilizers, antifoaming agents, and plasticizers other than the aqueous polyurethane resin composition. Ordinary paint additives such as surface conditioners can be blended.

  As said other resin, a polyester resin, an acrylic resin, a polyether resin, a polycarbonate resin, an epoxy resin, an alkyd resin etc. can be used. These are used alone or in combination of two or more.

  Examples of the coating method using the aqueous polyurethane resin composition of the present invention include brush coating, roller coating, spray coating, gravure coating, reverse roll coating, air knife coating, bar coating, curtain roll coating, dip coating, Any means such as a rod coat or a doctor blade coat may be used. The aqueous polyurethane resin composition of the present invention is applied to the substrate by means appropriately selected from these.

  Hereinafter, the present invention will be specifically described by way of examples. In the following examples and the like, the blending ratio (%) means a mass-based ratio unless otherwise specified.

[Synthesis of Polyisocyanate Component (PP-B)]
In a 5-neck separable round bottom flask equipped with a Dimroth, a stirring blade and a nitrogen line, 575 g (3.02 equivalents) of 1,6-hexamethylene diisocyanate isocyanurate (trimer), stearyl alcohol (n-octa) Decanol) was added in an amount of 270 g (1.0 equivalent), and the mixture was allowed to react at 115 to 120 ° C. for 2 hours under a nitrogen stream, confirming that NCO% was 9.98%. Thus, an isocyanate compound (hereinafter referred to as “PP-B”) was obtained. PP-B is a compound represented by the above formula (1) in which the group A is a residue obtained by removing two isocyanate groups from 1,6-hexamethylene diisocyanate.

[Example 1]
(Synthesis of urethane prepolymer)
The following raw materials were sealed in a 5-neck separable round bottom flask equipped with a Dimroth, a stirring blade, and a nitrogen line.
(A) Polyol component:
Adeka polyol YG-108 (polyester diol having a number average molecular weight of 935, manufactured by ADEKA) 318 g (0.68 equivalent), and
-Adeka polyol BPX-11 (propylene oxide adduct of bisphenol A, manufactured by ADEKA Corporation) 29.5 g (0.16 equivalent).
(B) Polyisocyanate component:
-PP-B 126g (0.30 equivalent, (b) about 27% of the total amount of polyisocyanate component),
-2,4-tolylene diisocyanate 23.2 g (0.27 equivalent), and
-316 g (2.41 equivalents) of 4,4'-dicyclohexylmethane diisocyanate.
(C) Anionic group introducing agent: 54.9 g (0.82 equivalent) of dimethylolpropionic acid.
Solvent: 351 g N-methylpyrrolidone.
The above raw materials were reacted at 100 to 120 ° C. for 3 hours in a nitrogen stream. Then, after confirming that NCO% became 3.39%, 2.5 g of benzotriazole and 6.5 g (0.03 equivalent) of γ-aminopropyltriethoxysilane were added, and the mixture was further stirred for 30 minutes. Thereafter, the reaction system was cooled to 60 ° C., 41.4 g (0.41 equivalents) of triethylamine was added, and the mixture was stirred for 30 minutes to obtain a urethane prepolymer PP-01.

(Synthesis of water-based polyurethane resin composition)
After adding 894.5 g of water and 0.6 g of Adecanate B-1016 (antifoaming agent, manufactured by ADEKA Corporation) to a 2 L disposable cup equipped with a disper, the temperature in the reaction system should not exceed 40 ° C. A total of 628.5 g (0.49 equivalent of NCO group) of PP-01 was gradually added. After completion of the addition of PP-01, the mixture was stirred at 20 to 35 ° C. for 30 minutes, and then 54.3 g (0.26 equivalent) of 2-aminoethylaminoethanol aqueous solution having a concentration of 25% by mass as (B) chain extender And 4.2 g (0.05 equivalent) of adipic acid dihydrazide was added, and also it stirred at 20-35 degreeC for 1 hour, and obtained the aqueous | water-based polyurethane resin composition U-1.

(Evaluation of water-based polyurethane resin composition)
The following various evaluation was performed about the obtained water-based polyurethane resin composition U-1. The results are shown in Table 1.

-Elongation rate, stress at break The water-based polyurethane resin composition was applied to one side of a PET film so as to have a film thickness of 100 μm using a bar coder. This was left to stand at 25 ° C. for 24 hours and then dried at 120 ° C. for 1 hour. Thereafter, the PET film was peeled off to obtain a urethane film. Based on JIS-K-6251, the obtained urethane film was subjected to a tensile test under the conditions of a test speed of 500 mm / min, a span interval of 40 mm, and a marked line interval of 20 mm, and the film elongation and break stress were measured.

-Adhesiveness with respect to steel plate The water-based polyurethane resin composition was apply | coated by 1 micrometer thickness on an untreated electrogalvanized steel plate. This was heated and dried for 15 seconds in an atmosphere of 300 ° C. (conditions where the maximum reached temperature of the steel sheet was 150 ° C.) to obtain a test piece to which a urethane resin film adhered. Based on JIS K 5600-5-6, the coating film was cross-cut from the test piece, the degree of peeling by the tape was observed, and the adhesion of the coating film to the electrogalvanized steel sheet was evaluated according to the following criteria. Rank 5 has the highest adhesion, and rank 1 has the lowest adhesion.
Rank 5: No abnormality in coating film.
Rank 4: The coating film peels slightly (less than 5% of the entire area).
Rank 3: The coating film is peeled off slightly (5% or more and less than 20% of the entire area).
Rank 2: Most of the coating film (20% or more and less than 50%) is peeled off.
Rank 1: Most of the coating film (50% or more) peels off.

-The water-resistant water-based polyurethane resin composition was apply | coated by 1 micrometer thickness on an untreated electrogalvanized steel plate. This was heated and dried for 15 seconds in an atmosphere of 300 ° C. (conditions where the maximum reached temperature of the steel sheet was 150 ° C.) to obtain a test piece to which a urethane resin film adhered. The test piece was immersed in warm water at 40 ° C., the state of the coating film after 1 hour was observed, and the water resistance of the coating film was evaluated according to the following criteria. Rank 5 has the highest water resistance, and rank 1 has the lowest water resistance.
Rank 5: No abnormality in coating film.
Rank 4: The coating film peels slightly (less than 5% of the entire area).
Rank 3: The coating film is peeled off slightly (5% or more and less than 20% of the entire area).
Rank 2: Most of the coating film (20% or more and less than 50%) is peeled off.
Rank 1: Most of the coating film (50% or more) peels off.

-The corrosion-resistant water-based polyurethane resin composition was apply | coated by 1 micrometer thickness on an untreated electrogalvanized steel plate. This was heated and dried for 15 seconds in an atmosphere of 300 ° C. (conditions where the maximum reached temperature of the steel sheet was 150 ° C.) to obtain a test piece to which a urethane resin film adhered. Based on JIS K 5600-7-1, the salt spray test of this test piece was done. The test piece was observed for white rust after 24 hours, and the corrosion resistance was evaluated according to the following criteria. Rank 5 has the highest corrosion resistance, and rank 1 has the lowest corrosion resistance.
Rank 5: White rust occurrence rate is less than 5% with respect to the entire test piece.
Rank 4: White rust occurrence rate is 5% or more and less than 20% with respect to the entire test piece.
Rank 3: The white rust occurrence rate is 20% or more and less than 50% with respect to the entire test piece.
Rank 2: The white rust occurrence rate is 50% or more and less than 80% with respect to the entire test piece.
Rank 1: White rust occurrence rate is 80% or more with respect to the entire test piece.

-Alkali-resistant water-based polyurethane resin composition was apply | coated by 1 micrometer thickness on an untreated electrogalvanized steel plate. This was heated and dried for 15 seconds in an atmosphere of 300 ° C. (conditions where the maximum reached temperature of the steel sheet was 150 ° C.) to obtain a test piece to which a urethane resin film adhered. The test piece was immersed in a 60 ° C. aqueous solution (pH 12), the state of the urethane coating film after 10 minutes was observed, and the alkali resistance was evaluated according to the following criteria. Rank 5 has the highest alkali resistance, and rank 1 has the lowest alkali resistance.
Rank 5: No abnormality in coating film.
Rank 4: The coating film peels slightly (less than 5% of the entire area).
Rank 3: The coating film is peeled off slightly (5% or more and less than 20% of the entire area).
Rank 2: Most of the coating film (20% or more and less than 50%) is peeled off.
Rank 1: Most of the coating film (50% or more) peels off.

-Adhesiveness with top coat The water-based polyurethane resin composition was applied to an untreated electrogalvanized steel sheet in a thickness of 1 µm. This was heated and dried for 15 seconds in an atmosphere of 300 ° C. (conditions where the maximum reached temperature of the steel sheet was 150 ° C.) to obtain a test piece to which a urethane resin film adhered. Next, a melamine-based paint (Amirac # 1000, manufactured by Kansai Paint Co., Ltd.) was applied in a thickness of 25 μm on the side of the test piece on which the urethane resin film was adhered, and baked at 125 ° C. for 20 minutes. This was left to stand for 24 hours and then immersed in boiling water for 2 hours. This was left still for 24 hours. Then, in accordance with JIS K 5600-5-6, the coating film was cross-cut and subjected to an extrusion process of 7 mm using an Erichsen testing machine, and then the degree of peeling of the top coating material with the tape was observed. The adhesion was evaluated according to the following criteria. Rank 5 has the highest adhesion, and rank 1 has the lowest adhesion.
Rank 5: No paint peeling.
Rank 4: The paint peels slightly (less than 5% of the entire area).
Rank 3: The paint is peeled off slightly (5% or more and less than 20% of the entire area).
Rank 2: Most of paint (20% or more and less than 50%) is peeled off.
Rank 1: Most of the paint (50% or more) peels off.

[Example 2]
Urethane prepolymer PP-01 was synthesized in the same manner as in Example 1. (B) As chain extender, except that 30.8 g (0.15 equivalent) of 2-aminoethylaminoethanol aqueous solution having a concentration of 25% by mass and 13.3 g (0.16 equivalent) of adipic acid dihydrazide were added. An aqueous polyurethane resin composition was synthesized under the same conditions as in Example 1 to obtain an aqueous polyurethane resin composition U-2. The obtained U-2 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
Urethane prepolymer PP-01 was synthesized in the same manner as in Example 1. (B) As a chain extender, 92.0 g (0.44 equivalent) of 2-aminoethylaminoethanol aqueous solution having a concentration of 25% by mass was added, and the same conditions as in Example 1 except that adipic acid dihydrazide was not added. An aqueous polyurethane resin composition was synthesized to obtain an aqueous polyurethane resin composition U-3. The obtained U-3 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Example 1]
PP-B was not used in the synthesis of the urethane prepolymer. That is, (b) 2,4-tolylene diisocyanate 23.2 g (0.27 equivalents) and 4,4′-dicyclohexylmethane diisocyanate 355.3 g (2.71 equivalents) were used as the polyisocyanate component. Polymer PP-02 was synthesized. The water-based polyurethane resin composition U-4 was obtained on the same conditions as an Example except having used PP-02 as a urethane prepolymer. The obtained U-4 was evaluated in the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 2]
Urethane prepolymer PP-01 was synthesized in the same manner as in Example 1. In the synthesis of the water-based polyurethane resin composition, (B) chain extender not containing 2-aminoethylaminoethanol was used. That is, an aqueous polyurethane resin composition was synthesized under the same conditions as in Example 1 except that (B) 25.7 g (0.31 equivalent) of adipic acid dihydrazide was added as a chain extender, and the aqueous polyurethane resin composition U- 5 was obtained. The obtained U-5 was evaluated in the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 3]
Urethane prepolymer PP-01 was synthesized in the same manner as in Example 1. In the synthesis of the water-based polyurethane resin composition, (B) chain extender not containing 2-aminoethylaminoethanol was used. That is, under the same conditions as in Example 1 except that 4.2 g (0.05 equivalent) of adipic acid dihydrazide and 15.9 g (0.26 equivalent) of 2-aminoethanol were used as the chain extender (B). An aqueous polyurethane resin composition was synthesized to obtain an aqueous polyurethane resin composition U-6. The obtained U-6 was evaluated in the same manner as in Example 1. The results are shown in Table 1.

The following abbreviations are used in Table 1.
2,4-TDI: 2,4-tolylene diisocyanate 4,4′-DCHMDI: 4,4′-dicyclohexylmethane diisocyanate 2-AEAE: 2-aminoethylaminoethanol 2-AE: 2-aminoethanol ADH: adipic acid Dihydrazide As shown in the evaluation results of Table 1, the comparative aqueous polyurethane resin composition U-4, which did not use the isocyanate compound represented by the above formula (1), was inferior in water resistance and corrosion resistance. Not suitable for paint. The comparative water-based polyurethane resin composition U-5, U-6, which did not use 2-aminoethylaminoethanol, is inferior in performance in any one or more of corrosion resistance, alkali resistance, and adhesion to top coating, It is not suitable for undercoating or intermediate coating on steel sheets. On the other hand, the water-based polyurethane resin compositions U-1, U-2, U-3, which are examples of the present invention, are all adhesiveness to steel sheets, water resistance, corrosion resistance, alkali resistance, and adhesion to top coating. Is excellent as a paint for steel plates.

Applications of the water-based polyurethane resin composition of the present invention are expected to be paints, adhesives, surface modifiers, organic and / or inorganic powder binders, and molded products. The water-based polyurethane resin composition of the present invention excels in performance such as adhesion to a steel sheet, water resistance, corrosion resistance, and alkali resistance, and is also excellent in adhesion to a top coating. Therefore, the water-based polyurethane resin composition of the present invention is particularly useful as an undercoat for steel sheets, an intermediate coat paint, and a paint for metal surface treatment agents. Since the metal material to which the paint using the water-based polyurethane resin composition of the present invention is applied can be applied in a wide range of fields such as home appliances, automobiles, and building members, the present invention is extremely useful industrially.

Claims (6)

The (A) urethane prepolymer obtained by reacting (a) a polyol component, (b) a polyisocyanate component, and (c) a component containing an anionic group introducing agent has a concentration of the (A) urethane prepolymer of 10 to 10. An aqueous polyurethane resin composition obtained by dispersing in water so as to be 70% by mass, and then reacting (A) the urethane prepolymer in the obtained aqueous dispersion with (B) a chain extender,
The (b) polyisocyanate component contains an isocyanate compound represented by the following general formula (1),
The (B) chain extender contains 2-aminoethylaminoethanol,
An aqueous polyurethane resin composition.

(B) The water-based polyurethane resin according to claim 1, wherein the polyisocyanate component includes an isocyanate compound in which the group A in the formula (1) is a residue obtained by removing two isocyanate groups from 1,6-hexamethylene diisocyanate. Composition. (B) The water-based polyurethane resin composition of Claim 1 or 2 in which a polyisocyanate component contains the isocyanate compound represented by the said Formula (1) of the quantity of 10-50 mass% with respect to the whole quantity. (B) The polyisocyanate component further contains one or more compounds selected from tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and 4,4-dicyclohexylmethane diisocyanate. 4. The aqueous polyurethane resin composition according to any one of 3 above. (B) The water-based polyurethane resin composition in any one of Claims 1-4 in which chain extender contains 2-aminoethylaminoethanol of the quantity of 30-90 mass% with respect to the whole quantity. The coating material which uses the water-based polyurethane resin composition in any one of Claims 1-5.